I. Field
The present disclosure relates generally to wireless communications and more specifically to multi-carrier transmission in a single frequency band.
II. Background
Wireless communication systems are widely deployed to provide various types of communication content such as, for example, voice, data, and so on. Typical wireless communication systems may be multiple-access systems capable of supporting communication with multiple users by sharing available system resources (e.g., bandwidth, transmit power, . . . ). Examples of such multiple-access systems may include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, and the like. Additionally, the systems can conform to specifications such as third generation partnership project (3GPP), 3GPP long term evolution (LTE), ultra mobile broadband (UMB), etc., and can use one or more protocols, such as high-speed uplink packet access (HSUPA), single carrier HSUPA (SC-HSUPA), dual carrier HSUPA (DC-HSUPA), etc.
Generally, wireless multiple-access communication systems may simultaneously support communication for multiple mobile devices. Each mobile device may communicate with one or more access points (e.g., base stations, femtocells, picocells, relay nodes, and/or the like) via transmissions on forward and reverse links. The forward link (or downlink) refers to the communication link from access points to mobile devices, and the reverse link (or uplink) refers to the communication link from mobile devices to access points. Further, communications between mobile devices and access points may be established via single-input single-output (SISO) systems, multiple-input single-output (MISO) systems, multiple-input multiple-output (MIMO) systems, and so forth. In addition, mobile devices can communicate with other mobile devices (and/or access points with other access points) in peer-to-peer wireless network configurations.
Mobile devices operating using SC-HSUPA can transmit over a single carrier at during a given period of time. For example, mobile devices can apply channel coding and multiplexing, spreading, a pulse shaping radio resource control filter, and/or the like to media access control (MAC) or similar layer communications. It is to be appreciated that spreading can include channelization (e.g., transforming a data symbol into a number of chips to increase bandwidth of the signal) and scrambling (e.g., applying a scrambling code to the spread signal). Thus, data symbols on I- and Q-branches can be independently multiplied with an orthogonal variable spreading function code during channelization, and the resultant signals on the I- and Q-branches can be further multiplied by complex-valued scrambling code, where I and Q are real and imaginary parts, respectively, for example. Mobile devices can convert the I and Q branches to an analog signal via a digital-to-analog converter and/or low pass filter. Subsequently, mobile devices can up-convert the analog signal to a radio frequency and transmit the signal to one or more devices or access points. Mobile devices can additionally utilize a power amplifier to increase power utilized for the transmission.